Sewing machine



Oct. 10, 1944. 'N. v. CHRISTENSEN ,360,0 8

SEWING MACHINE Filed Aug. 5, 1941 9 Sheets-Sheet 1 Oct. 10, 1944. N, CHRISTENSEN 2,360,048

SEWING MACHINE 4, AT TaR/VEY wwu 9 Sheets-Sheet 4 L Ag Ni V. CHRISTENSEN SEWING MACHINE Filed Aug. 5, 1941 h H H m h m H M Oct. 10, 1944.

TNVEIVTOR A T'TOR/VE Oct. 10, 1944. v CHRISTENSEN 2,360,048

SEWING MACHINE Filed Aug. 5, 1941 9 Sheets-Sheet 5 I/VVENTOR 4a., ATTORNEZ 1944. N. v. CHRISTENSEN 2,360,048

SEWING MACHINE Filed Aug. 5, 1941 9 Sheets-Sheet 6 illl/ IN VEN TOR my BY OATTOR Y Oct. 10, 1944. N, CHRISTENSEN 2,360,048

SEWING MACHINE Filed Aug. 5, 19% 9 Sheets-Sheet 8 FIG m l ll lll fllulmi U5 Q I INVENTOR N m a BY ed. A TTORNE Y 1944- N. v. CHRISTENSEN 2,360,048

SEWING MACHINE Filed Aug. 5, 1941 9 Sheets-Sheet 9 INVENTOR BY 4.1 ATT RIVEY Patented Oct. 10, 1944 SEWING MACHINE Norman V. Christensen, Chicago, 11L, assignor to Union Special Machdne Company, Chicago, 111., a corporation oi Illinois Application August 5, 1941, Serial No. 405,539

4 Claims.

This invention relates to sewing machines and more particularly to an improved and simplified construction and arrangement of the parts of such machines. The present case is a continuation-in-part of my pending application Ser. No. 366,826, filed November 30, 1939, now Patent No. 2,294,074, granted August 25, 1942 and is directed to a divisible portion of the disclosure thereof.

A feature of the invention is the formation of a number of independent units or assemblies, each with its own frame structure, a plurality of the units being readily connected to form a com plete machine. In a preferred form of the invention, certain of the units are adapted for interchangeable connection with another, so that machines of difierent types or intended for difierent purposes may be produced by coupling togather appropriately selected units. This not only simplifies the assembly of individual machines, due to their unit construction, but also enables large-scale production of the several units. A unit capable of employment in a number of different styles of machines may be produced in relatively large quantities, thus reducing the cost of the unit.

In the preferred application of the invention, a feed-ofi-the-arm type of machine may be formed in two separate units,a base unit and an upper arm unit, the later having a vertical standard at one end adapted to be readily connected with or disconnected from the base unit. The arrangement is such that the driving connections between the two units are completely coupled upon merely connecting together the frames of the units. Moreover, the upper arm unit, with its standard, is such that it may be used interchangeably with the feed-off-the=-arm base unit or with a fiat bed unit by simply attaching the standard to the frame of the selected base. Other base units may likewise be used interchangeably with the same upper arm unit. So also, a single base unit may, if desired, be adapted for interchangeable use with different upper arm units.

Due to the simplicity of the connection and disconnection of the several units, a single upper arm, for example, may be provided with several base units, which may be used, as desired, for the performance of different types of work. But a primary advantage of the interchangeability of the units is that the production of difierent types of machines may be simplified and their cost reduced to a minimum.

Various novel constructions and arrangements are embodied in the several units forming part of the present invention. The feed-off-the-arm base unit, for example, when coupled with the upper arm unit combines the advantages of a number of prior feed-ofl-the-arm machines. It is simple in construction, easy to assemble, convenient to operate and capable of operation at high speed. Toward these ends the work arm of this base unit has only two sides which are at substantially a right angle to each other and are disposed substantially horizontally. Zirconium:- tion with the upper arm, the work arm prac= tically presents, in plan, the configuration of a right-angled triangle.

In general, it has been an object of the invention to so construct the several units that each is relatively small and compact, utilizes rotary motion to the greatest extent possible, may be operated at high speeds with a minimum of vibration, and may be quickly started and stopped without injury to the mechanism.

-Another object of the invention has been to avoid, as far as possible, the provision of internal projections on the machine. This has been accomplished through the provision of a frame, the outer surfaces of which are well rounded andv smooth and which affords, at its interior, a series of chambers or cavities for the accommodation not only of the stitch forming, feed, and driving mechanisms, but also of the thread tensions and mechanism for lifting the presser element and means for controlling the tensions for the needle and looper threads.

Still another object of the invention is to pro- I vide within a hollow frame, of the character above specified, isolated chambers in which the needle mechanism, the feed mechanism, the drive mechanism and other driven parts of the machine are separately housed, said chambers having separate oil supply provisions for automatic lubrication of the several mechanisms. Other objects and attendant advantages will appear from a detailed description of an illustrative form of the invention which will now be given in conjunction with the accompanying drawings, in which: t

Figure I is a plan view of a complete sewing machine of the feed-ofi-the-arm type, a portion of the frame or housing of the upper unit being broken out at the top to expose a part of the interior.

Figure II is a view partly in front elevation and partly in vertical section, taken along the line 11-11 in the direction of the arrows of Figure I.

Figure 111 is a horizontal, sectional view through the base and work supporting arm of the lower unit of the machine, taken along the line III-III of Figure II in the direction of the arrows in Figure 11.

Figures IV, V, VI, VII and VIII are vertical sectional views, taken transversely at intervals along the work supporting arm, at the points indicated, respectively, by the lines and arrows IV--IV, V-V, VI-VI, VII-VII and VIII-VIII in Figures In, 1x and x Figure IX is a detailed view showing in section, along the line IX-IX and in the direction of the arrows in Figure III, the anchorage portion of the work arm.

Figure X is a vertical sectional view through the free end of the work arm along the line X-X of Figure III and taken in the direction indicated by the arrows, the lower portion of the needle head and associated devices being disclosed in elevation.

Figure X! is a front elevation of the needle head of the machine with its cover plate removed to expose the interior of the mechanism.

Figure XII is a side elevation of a portion of the work supporting arm of the lower unit of the machine, a portion of the frame"or housing being broken away to expose the thread tensioning mechanism,

Figure XIII is a plan view of the upper unit of the machine, with a portion broken away to show the presser foot lifting mechanism and with a part adjacent the right end omitted.

Figure XIV is a transverse. sectional view through the overhanging arm taken along the line XIV-XIV of Figure I in the direction oi the arrows.

Figure XV is a perspective view showing the two units of the machine in spaced position prior to assembly.

Figure XVI is a view, partly in side elevation and partly in section along the line XVI-XVI of Figure XVII, showing an upper unit of the type disclosed in Figures I to XV, inclusive, applied to a diflerent base unit, i. e., that of a flat bedmachine.

Figure XVII is a horizontal, sectional view along the line XVII-XVII of Figure XVI through the flat bed base unit, and

Figure XVIII is a perspective view of the entire flat bed base ,unit.

Referring now to Figures XV and XVIII, there is disclosed an upper unit A comprising a vertical standard portion and a horizontally extending upper arm portion, which will be described hereinafter in greater detail. Beneath the upper unit in Figure XV there is shown a feedoif-the-arm unit B adapted to be connected with the upper unit to form a complete machine. As will be e plained in greater detail hereinafter, the coupling of the two units A and B requires simply the placing of the upper unit in correct position on the lower unit and securing these units together by means of appropriate screws or bolts. The only driving or operating connection between the two units is the gearing indicated in Figure XV, which will be hereinafter more fully described.

The upper unit A is also adapted to be combined with a base unit C (Figure XVIII) to form a complete fiat bed type of machine. Here again, the connection of the two units A and requires simply the proper application oi one to the other and the insertion and tightening of a series of bolts or screws. The driving or operating connection between the two units is accomplished entirely through the gearing indicated.

Turning now to Figures I to XV, inclusive, the construction of the feed-ofl-the-arm machine, produced by combining units A and B, will be described. Referring particularly to Figure I, the improved machine has a frame which comprises a base portion I of the lower unit, which is of substantially rectangular configuration and from which extends, horizontally at an angle, an anchorage portion 2 of a work arm 3, the free end 4 Of which is disposed at substantially a right angle to the anchorage portion 2 and lies in the same horizontal plane with the latter.

From Figures II and III, it will be observed that the base portion I has a chamber 5 and that the work arm 3 is also hollow and has the connecting end of its anchorage portion 2 in direct communication with the chamber in the base. Rising from the base portion I and secured thereto by screws or bolts 9 is a vertical standard I which is hollow and communicates openly with the chamber 5 of said base portion, said standard forming part of the upper unit and supporting a horizontal, overhanging arm I which terminates in a'needle head 8. As viewed in Figure I, the overhanging arm I forms a triangle with the portions. 2 and 4 of the work arm 3 and has the needle head at its outer end directly above the free end of the terminal portion 4 of said work arm. The screws 9 are passed upwardly through passages in the base portion, and have threaded engagement with openings in a flange at the bottom of the standard 6. This forms the only connection to be made or undone between the two units A and B.

For operation of the machine, a combined hand wheel and belt pulley II is provided; and beneath the pulley element the base portion I is slotted, as indicated at I2, for passage of a conventional driving belt. The combined hand wheel and belt pulley I I is afllxed to a driving shaft I3 which extends longitudinally of the overhanging arm I, and which is joumaled in suitable bearings I4, I5 and I6. At its distal end (Figures II and XI), the driving shaft I3 enters I the needle head 8 and drives a crank disc I'I carrying a crank pin I8. By means of a link II, the crank pin I8 is connected to a pin 2I forming an integral part of a clamp collar 22 carried by the needle bar 23. The free end of the pin 2| extends beyond the end of the link I9 and is formed with flattened sides which engage guide plates 24 secured to the inner face of the needle head by screws 25, thus resisting any torsional forces exerted by the link I9. The needle bar 23 is mounted for reciprocation in suitable bearing bushings 2B in the needle head 8 and atits lower end carries one or more needles 21 (three such needles being shown in the illustrated example, Figure X) which cooperate with complemental stitch forming mechanism situated in the free endof the work arm to effect the formation of stitches.

As best illustrated in Figure II, the bearing bushings IS, IS are mounted in cross walls 23, 29 in the overhanging arm I which serve to divide that arm into three compartments, namely, a needle head compartment 3|, a gear compartment 32 within the hollow standard 3, and an intermediate compartment 33 in which suitable needle thread tensions 34 are mounted on a bracket plate 35 secured by screws 3. Access to the intermediate compartment 3: is bad through a cover plate 31 mounted by hinges 33 on the overhanging arm of the machine. As shown In Figure I, the needle threads n pass from a source of supply through eyelets 39, mounted in the rear wall of the overhanging arm, thence through the tension devices 34, and through eyelets 4| in the front wall of the overhanging arm, and ultimately through suitable guides and take-up members 42, 43 and 44 to the needles 21.

Secured in the lower portion of the needle head 8 by a set screw 45 (Figure X1) is 8. depending bar 46 on which is mounted a collar 41 (Figures 11 and X) rigidly secured thereto. The collar 41 is provided with laterally extending lugs 48, 49 in which a presser bar carrying at its lower end a presser foot 52, is mounted for vertical movement. The presser bar 5| adjacent the presser foot 52 is provided with a laterally extending tongue member 53 which engages a slot 54 formed in the lower end of the depending bar 46, thus resisting any tendency of the presser bar 5| and presser foot 52 to turn about the axis of the presser bar. At its upper end the collar 41 is further provided with a rearwardly extending arm 55, which at its outer end has a notch 56 accommodating one end of a leaf spring 51. The leaf spring 51 at its other end engages the end of the presser bar 5| and through an adjustable screw 58 tends to urge the presser foot into yielding engagement with the work on the work arm 3. By means of the screw 58, the pressure exerted by the spring 51 on the presser bar 5| and presser foot 52 may be varied. Between the guiding lugs 48, 49 the presser bar 5| carries a shoulder screw 59 which, through a flexible member 6|, is connected with a crank arm 62 (Figures XI and XIII), afiixed to a rock shaft 63 joumaled in bearings 64, 65 in the overhanging arm of the machine. The endwise movement of this rock shaft 63 is prevented by engagement of the opposite ends of the bearing 64 by the hub of the arm 62 and a thrust collar 66. Adjacent the bearing 65 the rock shaft 63 carries a collar 61 clamped thereto and having a laterally projecting crank arm 68, extending through a clearance opening in the wall of the overhanging arm of the machine, the free end of which is adapted to be engaged by a chain or other suitable means leading to a foot treadle or the like for rocking the shaft and thereby lifting the presser foot 52 from contact with the work on the work support. The collar 61 is further provided with a laterally projecting lug 69 which extends beneath the tension devices 34 and upon rocking of the shaft 63 to lift the presser foot 52, this lug 69 will engage the release pins II of the tension members 34, and separate the tension discs I0 (see Figures II, XIII and XIV). From Figure II, it is to be particularly noted that the flexible connecting member 6I extends through a tube 60 within the hollow of the head 8, the top of said tube being well above the level of an oil supply (conventionally indicated) at the bottom of said head and out of the range of oil splashed by the moving parts of the needle actuating mechanism.

Within the hollow standard 6, the driving shaft I3 carries a pinion 12 which meshes with an idler gear 13 joumaled for rotation on a stationary shaft 14, and the idler gear 13 in turn meshes with a second pinion 15, identical to the pinion I2 mounted on a short countershaft l6 joumaled in bearings ll, I8 in the upstanding portion 19 of the base I. The chamber 5 in this portion of the base is closed at the bottom by a cover plate 8| and gasket 82, thus providing, in conjunction with the hollow standard, an oil-tight compartment in which the above-mentioned gears operate. As will be seen the gear l5 dips into the lubricant in the compartment or reservoir mentioned and, therefore, when operated, serves to throw a fine spray of the lubricant into the standard to lubricate the various surfaces requiring it. A part of the lubricant will be collected in the reservoir 15a. at the lower end of the standard and from this will be delivered through the passage 15b to the bearing 11 and will then be returned to the compartment. The gears I3 and I5 form the only driving connection between the upper and lower units so that these are automatically coupled for operation upon simply securing the frames of the two units together.

With particular reference to Figures 111, IX and X, wherein the mechanism within the work supporting arm 3 may be viewed in detail, it will be observed that the shaft I6 in addition to the gear 15 carries a bevel gear 83 which meshes with an identical bevel gear 84 afllxed to one end of a transmission shaft 85 joumaled in bearing bushings 86, 81 and 88, supported, respectively by an interiorly projecting lug 89, a cross wall 9| and an end Wall 92 of the work supporting arm 3.

The connection from the shaft 85 for operating the complemental stitch forming devices and feed dog in the work arm and the particular form of these devices may be varied, as desired, but a construction and arrangement which is especially desirable for these purposes is disclosed herein and is disclosed and claimed in the application of Clarence 'C. Smith, Ser. No. 323,528, filed March 12, 1940.

At the free end of the work arm 3 in a compartment 93 are located one or more loopers 94, which constitute the complemental stitch forming means previously referred to (three such loopers being shown in the illustrated example). As shown, the loopers 94 are mounted in a holder 95 secured to the end of a looper shaft 96, which is joumaled for oscillation and endwise reciprocation in-bearings 91, 98 and 99 interiorly of the free end portion 4 of the work arm 3. Intermediate the bearings 98 and 99, the looper shaft 96 carries an arm I0| clamped thereto, which arm at its outer end isconnected by means of a link I02 to one end of a lever I03 for oscillation on a cross pin I04 carried by suitable formations in the interior of the work arm 3. The other end of the bell crank lever I03 is connected by a pitman I05 with a crank or eccentric member I06 on the shaft 95, located adjacent the bushing 01. Through the above described train of mechanism, the shaft 96 will be oscillated to give the loopers their taking and loop shedding movements.

Freely mounted on the looper shaft 96 is a collar I0! which is held against endwise movement by thrust collars I08. The collar I01 is provided with a laterally projecting stud I09 which is engaged by one end of a strap link III, the other end of which embraces an eccentric 2 on the shaft 85. As the shaft 85 is rotated. the eccentric II2, through this train of mechanism, will induce endwise reciprocation of the looper shaft, and thus impart to the loopers 94 their needle-avoiding movement. The collar I 01 is further provided with a depending lug H3, the flattened sides of which engage guide blocks I I4 secured by means of screws II6 to a boss 5 rising from the interior of the work arm. This guiding arrangement serves to absorb any torsion imparted to the collar I01 by the link IIE.

Secured to the forward end of the work arm 3 is a throat plate II1. having needle holes and feed dog slots H8 through which the sections of a four-motion feed dog II9 operate to engage the the side wall of the work arm at I45.

fabrics in the usual manner. The feed dog III is. provided with a depending shank I2I secured by means of a screw I22 to the forward end of a feed bar I22. The feed bar I22 extends lengthwise oi the work supporting end of the arm 2 and intermediate its ends is pivotally supported by the upper end of a vertical frame I24, which at its lower end is mounted for oscillation about a cross pin I" mounted in suitable bosses-I22 on the interior of the'work arm. At its rear end the feed bar I22 is provided with a longitudinal bore I2'I. in which a rod I22 is engaged for sliding reciprocation. This rod I22 is formed as an integral part of an eccentric strap I22 embracing an eccentric I2I on the .shaft 28. As'the shaft 22 revolves, the feed bar I22 will not be affected by the endwise components of motion of the rod I22, but the vertical component of its motion will cause the feed bar to oscillate about its pivotal support on the frame I24 and thus impart a rising and falling movement to the feed dog H2.

Pivotally connected to the feed bar I22 adjacent its pivotal support is a link I22, the other end of which is pivotally connected by a stud I22 in an arcuate slot I24 formed in a rock member I22 which at its lower end is pivotally mounted on a cross pin I22 secured in suitable lugs I21 projecting interiorly of the work arm 2. Pivotally connected to the rock member I22 is one end of a pitman I22, the other end 01' which embraces an eccentric I22 on the shaft 25. Rotation of the shaft 22 will impart oscillation to the rock member I22, and through the link I22 these oscillations will be converted into reciprocating movement in the feed bar for its feed and return stroke. By adjusting the rear end of the link I22 along the slot I24, the length of the feed stroke can be varied.

The looper thread or threads I are led from a source of supply into a slot I4I formed in the outer wall of the anchorage portion 2 of the work arm 2, and through this slot are led into a thread tension recess or cavity I42 formed in the rear side of the work arm. This recess or cavity I42 contains thread tension devices I42, and access thereto for the purpose of threading is had through a retractable cover plate I44 hinged to After passing through the thread tension devices I42, the looper thread is led through a slot I48 formed in the'upper rear wall of the work arm, and thence into a housing I" at the elbow oi the work arm formed by a hinged cover I42, and in the housing I41 there is located a suitable takeup device comprising a rotary cam I42 carried by the end of the shaft 22 and suitable thread guiding means including a slotted plate III secured to the end wall of the work arm bya screw I52 and slotted stripper blade I52, together with suitable thread guiding means including a pin I54 and thread guides I". From the take-up devices the thread I is led through a groove I56 formed in the upper edge of the side wall of the work arm 2 to the loopers-24. With particular reference to Figure III, the above described course of the looper threads I is indicated by dot-and-dash lines.

The entire work arm 2, including its anchorage portion 2, is closed at the top by a correspondingly configured cover plate I51 secured thereon by screws I22, as most clearly indicated in Figure I. Between the work arm 2 and the cover plate Ill, there is a gasket I52, which encloses the mechanism within the work arm in an oil-tight casing containing an oil bath. The

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cover plate I" extends lengthwise of the free end 4 of the work arm 2 beyond its point of attachment by the screws I22 and also extends along the anchorage portion 2 of the work arm beyond its point of attachment, and along this edge it is spaced to some extent from the edge of the work arm wall to provide an opening or slot I2I into which the thread I may be led to guide it into the thread guiding slots I4I, I42 and IN.

As may be seen irom the drawings, the mechanism oi the machine is enclosed in three oiltight compartments or chambers in each oi which a quantity of oil is encased for splash lubrication applied to the mechanism situated therein. These compartments are the needle head compartment 2i in which the parts are lubricated as already explained, the gear compartment 22 within the standard 2, which at its lower end extends laterally to the cross wall II in the work arm 2, and a compartment I22 extending along the work arm from the cross wall 2| to the cross wall 21 at the free end of the work arm 2. As a consequence of this arrangement, different grades of oil may be employed for the three diflerent mechanisms above referred to. Not only is a gasket employed to secure the cover plate I21 for the work arm including its anchorage portion, but an additional gasket I20 is also located between the cooperating upper and lower units A and B which are held together by screws, as explained.

For access to the loopers for inspection and threading, the work arm is provided at its free end with side openings, which are closed by covers I62 hinged at I62 and provided at their hinged point with cam surfaces I24 (Figure VIII) which engage the arms of a leaf spring I22 secured to the work arm 2 by a screw I82 and operating to hold the covers either in open or closed position.

From the above description, it will be particularly observed that the driving mechanism 01' the feed-oiI-the-arm sewing machine, produced by combining units A and B, comprises gear-connected shafts which extend from the standard 6 through the overhanging arm I and from the standard through the anchorage portion 2 of the work arm 2. Power is transmitted to points relatively remote from the standard by rotary elements exclusively. For imparting the desired movements (reciprocatory or oscillatory) to the needle bar 22, the loopers 24 and the feed dog II9, additional actuating mechanism, driven by said gear-connected shafts, is provided, which additional mechanism is confined to the needle head compartment 2| and the compartment Ill extending throughout the free end of the work arm 2. Thus, this invention materially reduces, from the standpoint of size and weight, the moving parts required for imparting such special movements to the stitch forming and feeding mechanism, permitting high speed operation, and at the same time resulting in obvious simplification, economy, and avoidance of vibration with respect to the entire driving mechanism. Moreover, the advantages of the co-planar type of work supporting arm are also obtained.

It will also be observed that numerous other advantages are gained, including especially an eiiicient system of ubrication for the moving parts most subject to wear, a convenient method of conducting the looper threads around an angular work supporting arm, and other advantages which follow from the particular design of the work supporting armand the accessibility of parts within the interior thereof.

Turning now to'Figures XVI to XVIII, there is disclosed a lower unit C of the flat bed type adapted to be combined with the same upper unit A as is disclosed in Figure XV and the earlier views. Preferably, the unit C is completely enclosed by an oil-tight frame or casing I10, having a top plate "I secured thereto by screws or the like, such as indicated at I12in Figure XVI. The cover plate, however, extends only from the forward end of the machine back to a portion I13 of the frame (Figures XVI and and XVIII), which rises to the top of the base unit at this point. The rear portion of the unit is provided with a large opening at the top, the surrounding wall of which is adapted to receive the standard of the upper unit A. Thus, a chamber I14 in open communication with the interior of the standard 6 is provided. Within the chamber I14 a spur gear I15 is mounted upon a shaft I18 journaled in a bearing I11 carried by the end wall of the frame I10. The forward end of this shaft is connected with a supplemental shaft I18 suitably joumaled in the frame and forming, in effect, an extension of shaft I16.

Gear I15 is secured to the shaft I16 by set screws I19 passing through the hub of the gear. It is suitably positioned to mesh with the gear 13 of the upper unit when the units A and C are properly assembled. At this time the bottom of the standard 8 rests upon the upper edges of the series of ears, I80 and II, extending rearwardly from the portion I13 of the frame. A gasket I83 is provided between the bottom of the standard 6 and the surfaces of the base member C upon which the standard rests. Screws or bolts I84, directed upwardly through openings in the ears I80 and I8I, and through passages I85 in the side walls of the frame, serve to secure the two units together. As in the case of the feedoff-the-arm machine, the connection between the upper and lower units is effected entirely by means of the screws or bolts I84, the operating connections between the two units bein automatically coupled through the engagement of the gears 13 and I15 as the two frames ar secured together.

The complementary stitch forming mechanism and the work feeding devices within the unit C may be of any suitable construction. That disclosed in the Christensen et al. Patent No. 2,128,- 120, granted August 23, 1938, may be employed. In general, it ma include a series of loopers I86, three being shown in Figure XVI, mounted on a carrier I81 adapted to be rocked through connections including a pitman I88, an arm I89 and a rock shaft I80, the latter being rocked by means of an eccentric I9I on the shaft I16 acting through connections including a pitman I92 and an arm I93.

A feed dog I94 (Figure XVIII) is carried by a feed bar I95 (Figure XVII) and receives a fourmotion movement through suitable connections from the shaft I16. These connections may be of the type disclosed in said Christensen et al. patent. As illustrated, the feed bar I95 may be pivotally carried at the upper end of a yoke I96, whose lower end is secured to a rock shaft I91 operated by an eccentric or crank I98, on the shaft I18, through a link I99. An up-and-down movement is imparted to the free end of the feed bar, which carries th feed dog, by another eccentric or crank, not shown, carried by the shaft I18. As the feed dog is raised, it is passed through the openings in a throat plate 200 carried by the top plate "I and forces the work against the under side of the presser foot 52.

Other suitable devices may be mounted in the frame I10 to meet the particular requirements of the machine. Thread tensioning devices may be so-mounted, if desired, and take-up mechanism for the loops of the looper threads may be operated by means on the shaft I18.

Adjacent the gear I15 there is secured to the shaft I16 2. disc 20I of relatively large diameter, the lower portion of which is immersed in the lubricant carried housing. Rotation of this disc causes the lubricant to be thrown through the opening at the top of the base unit into the connected standard 6 of the upper unit. This insures adequate lubrication of all of the driving and driven parts within the standard and the aligned portion of the base unit. The devices at the forward end of the base unit are efi'ec tively lubricated by the splash action of the various moving parts which dip into the oil.

While the invention has been described in some detail, with reference to a specific embodiment thereof, including an upper unit having a standard and overhanging arm, capable of interchange able application to either a feed-oif-the-arm base unit or a flat bed base unit, it will be understood that numerous changes may be made in the form and arrangement of th various parts without departing from the principles and scope of the invention. Various features of the invention may, at times, be used advantageously without association with other'features or devices disclosed herein. The terms and expressions employed in the foregoing have been used as terms of description and not of limitation.

What I claim is:

1. In a sewing machine a base member having a work support, a vertically disposed standard detachably connected with said base member, a horizontally disposed overhanging arm extending laterally from said standard adjacent its upper end and carrying a needle head above said work support, said standard and said base member having alined openings therein adapted to be brought into registry upon assembly of said standard and base member, cooperating stitch forming devices in said needle head and in said work support, means including a pair of parallel shafts in said arm and base member, respec- 4 tively, for synchronously driving said cooperating stitch forming devices, and driving connections between said shafts extending through said alined openings and adapted to be automatically connected and disconnected upon the assembly and disassembly of said standard and base memher, said driving connections forming the sole operating connections between the parts carried by said base member and by said standard and overhanging arm 2. In a sewing machine a base member having a work suport, a vertically disposed standard detachably connected with said base member, a horizontally disposed overhanging arm extending laterally from said standard adjacent its upper end and carrying a needle head above said work support, said standard and said base member having alined openings therein adapted to be brought into registry upon assembly of said standard and base member, cooperating stitch forming devices in said needle head and in said work support, means including a pair of parallel shafts in said arm and base member,respectively, i'or synchronously driving said cooperating stitch forming devices, and driving connections between said shafts extending through said alined openings and adapted to be automatically connected and disconnected upon the assembly and disassembly of said standard and base member, said driving connections including a pair of gears adapted to be meshed and unmeshed upon said assembly and disassembly of the standard and base member, said gears forming the sole operating connections between the parts carried by said base member and by said standard and overhanging arm.

3. In a sewing machine a base member having a work support, a .vertically disposed standard detachably connected with said base member, a horizontally disposed overhanging arm extending laterally from said standard adjacent its upper end and carrying a needle head above said work supp r said standard and said base member having alined openings therein adapted to be brought into registry upon assembly of said standard and base member, cooperating stitch forming devices in said needle head and in said work support, means including a pair of parallel shafts in said arm and base member, respectively,

for synchronously driving said cooperating stitch forming devices, and driving connections between said shafts extending through said alined openings and adapted to be automatically connected and disconnected upon the assembly and disassembly or said standard and base member,said driving connections including a pair of gears adaptedtobemeshedandunmeshed substantiallyintbeplaneotseparationbetweensaid standardandbasememberuponsaidassembly anddisa-emblyotthestandardandbasemcmber,saidgears forming thesoleoperating eonnectionsbetweenthepartscarriedbysaidbase memberandby saidstandardand overbandna arm.

amasewingmachineabasememberhaving an angled laterally extending work supporting arm, averticallydisposedstandarddetacbably iromsaidstandardadjacentitsupperendand carryinganeedleheadabovesaidworksupportingarm,saidstandardand saidbasemember having alined openings therein adapted to be brought into registry upon assembly 0! said standard and base member, cooperating stitch niormingdevicesinsaidneedleheadandinsaid work support, means including a pair of paralleishaitsinsaidarmandbasemembenrespectively, for synchronously driving said cooperating stitch forming devices, and driving connections between said shafts extending through said alined openings and adapted to be automatically connected and disconnected upon the assembly and disassembly of said standard and base members, said driving connections forming the soleoperatingoonnectionsbetweenflieparts' carried bysaidbasememberandbysaidstandard and overhanging arm.

NORMAN V. CHRISTENSEN. 

